It is well known in motor vehicle restraint systems to employ a seat belt retractor having a spring wound reel which retracts a belt to a taut condition about a seated occupant. It is also known to retract the belt about the occupant by attaching the belt to a carriage which is retracted linearly along a rectilinear track.
It has been recognized in the prior art that it would be desirable to provide a retractor which imposes a low spring effort on the belt when the belt is taut about the occupant to enhance the occupant's comfort, and yet the belt would be subjected to a relatively higher spring effort in order to effectively and assuredly retract the belt to a fully stored condition when the belt is unbuckled.
The present invention provides a new and improved retractor in which a seat belt reel winds a belt at a low spring effort and the reel is mounted on a linear track for retraction by a high effort spring to fully retract the belt from the occupant restraining position. A latching mechanism is provided to latch the reel to the track after the reel has been fully extended along the track so that the belt is freed from the high spring effort provided to retract the reel to thereby enhance occupant comfort.